# Patent

## Title
Antineoplastic peptides

## Abstract

The present invention provides antineoplastic peptides of formula I,









I



R1R2N-CHX-CO-A-B-D-E-(G)S-K






wherein R1, R2, X, A, B, D, E, G, K and s have the meanings stated in the description. The compounds have antineoplastic activity.

## Background
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/079,980, filed Mar. 31, 2008 which issued as U.S. Pat. No. 7,807,779, which is a divisional of U.S. patent application Ser. No. 11/179,074, filed Jul. 11, 2005 which issued as U.S. Pat. No. 7,368,528 on May 6, 2008, which is a divisional of U.S. patent application Ser. No. 09/757,142, filed Jan. 9, 2001, now abandoned, which is a continuation of U.S. patent application Ser. No. 09/097,184, filed Jun. 12, 1998, now abandoned, which is a continuation-in-part of International Application Serial No. PCT/EP96/05518, filed Dec. 11, 1996, which designated the United States, published in English, which claims priority to U.S. Provisional Patent Application Ser. No. 60/059,062, entitled “Antineoplastic Peptides”, which resulted from the conversion of U.S. patent application Ser. No. 08/573,422, filed Dec. 15, 1995, now abandoned.
The entire teachings of the above applications are incorporated herein by reference.


FIELD OF THE INVENTION
The invention described herein provides novel peptides and derivatives thereof which offer potentially improved therapeutic utilities for the treatment of neoplastic diseases as compared to dolastatin-10 and -15 (U.S. Pat. Nos. 4,879,276 and 4,816,444) and the compounds described in WO 93/23424.
SUMMARY OF THE INVENTION
Compounds of this invention include novel peptides of the formula i









I



R1R2N-CHX-CO-A-B-D-E-(G)S-K






where














R1
is hydrogen, methyl, or ethyl;


R2
is methyl; or ethyl; or


R1—N—R2
together are a pyrrolidine ring;


A
is a valyl, isoleucyl, alto-isoleucyl, 2-tert-



butyiglycyl, 2-ethylglycyl, norleucyl or 



norvalyl residue;


B
is a N-methyl-valyl, N-methyl-norvalyl, 



N-methyl-leucyl, N-methyl-isoleucyl,



N-methyl-2-tert-butylglycyl, N-methyl-



2-ethylglycyl, or N-methyl-norleucyl residue;


D
is a prolyl, homoprolyl, hydroxyprolyl, 



or thiazolidine-4-carbonyl residue;


E
is a prolyl, homoprolyl, hydroxyprolyl, 



or thiazolidine-4-carbonyl, trans-4-fluoro-



L-prolyl, cis-4-fluoro-L-prolyl, trans-4-



chloro-L-prolyl or cis-4-chloro-L-prolyl residue;


X
is ethyl, propyl, butyl, isopropyl, sec. butyl, 



tert.-butyl, cyclopropyl, or cyclopentyl;


G
is a L-2-tert.butylglvcyl, D-2-tert.butylglycyl, 



D-valyl, D-isoleucyl, D-leucyl, D-norvalyl,



1-aminopentyl-1-carbonyl, or 2,2-dimethylglycyl



residue;


S
is 0 or 1;


K
is —NH—C1-8-alkyl, —NH—C3-8-alkenyl, 



—NH—C3-8-alkinyl, —NH—C6-8



cycloalkyl, —NH—C1-4-alkene—C3-8cycloalkyl, 



C1-4-alkyl—N—C1-6-alkyl, in which residues



one CH2 group may be replaced by O or 



S, one H by phenyl or cyano, or 1, 2 or 3 H



by F, except the N-methoxy-N-methylamino,



N-benzylamino, or N-methyl-N-benzylamion 



residue, or K is













and the salts thereof with physiologically tolerated acids



DETAILED DESCRIPTION OF THE INVENTION
In specific embodiments of the compounds of formula I, K may be —NHCH3, —NHCH2CH3, —NH(CH2)2CH3, —NH(CH2)3CH3, —NH(CH2)4—CH3, —NH(CH2)5CH3, —NH(CH2)6CH3, —NHCH(CH2)7CH3, —NHCH(CH3)2, —NHCH(CH3)CH2CH3, —NHCH(CH2CH3)2, —NHCH(CH2CH2CH3)2, NHC(CH3)3, NHCH(CH2CH3)CH2CH2CH3, —NHCH(CH3)CH(CH3)2, —NHCH(CH2CH3)CH(CH3)2, —NHCH(CH3)C(CH3)3, —NH-cyclohexyl, —NH-cycloheptyl, —NH-cyclooctyl, —N(CH3)OCH2CH3, N(CH3)OCH2CH2CH3, —N(CH3)OCH(CH3)2, —N(CH3)O(CH2)3, —N(CH3)OCH2C6H5, —NH(CH2)2C6H5, —NH(CH2)3C6H5, —NHCH(CH3)C6H5, —NHC(CH3)2C6H5, —NHC(CH3)2CH2CH3, —NHC(CH3)(CH2CH3)2, —NHCH[CH(CH3)2]2), —NHC(CH3)2CN, —NHCH(CH3)CH(OH)C6H5, —NHCH2-cyclohexyl, NHCH2C(CH3)3, —NHCH2CH(CH3)2, —N(CH3)2, —N(CH2CH3)2, —N(CH2CH2CH3)2, —NHCH2CF3, —NHCH(CH2F)2, —NHCH2CH2F, —NHCH2CH2,OCH3, —NHCH2CH2SCH3, —NHCH2CHCH2, —NH—C(CH3)2CH═CH2, —NHC(CH3)2,C≡CH, —NHC(CH2CH3)2C≡CH, —NHC(CH3)2CH2CH2OH, —NH(CH2CH2O)2CH2CH3, —NHC(CH3)2CH(CH3)2, —NHC(CH3)2CH2CH2CH3, —NHC(CH3)2CH2—C6H5, —N(OCH3)CH(CH3)2—N(OCH3)CH2CH3, —N(OCH3)CH2CH2CH3, —N(OCH3)CH2C6H5, —N(OCH3)C6H5, —N(CH3)OC6H5, —NHCH[CH(CH3)2]2, —N(OCH3)CH2CH2CH2,CH3, or the special ring systems mentioned above.
In one embodiment of the compounds of formula I described above, s is 0 and E is homoprolyl or hydroxyprolyl.
Preferred are compounds of the formula I where the substituents R1, R2, A, B, D, E, X, G and s have the following meanings:

    R1 hydrogen, methyl, or ethyl, especially methyl;
    R2, methyl or ethyl, especially methyl;
    A valyl, valyl, isoleucyl, 2-tert-butylglycyl, 2-ethylglycyl, norleucyl or norvalyl, especially valyl, isoleucyl, 2-tert-butylglycyl, 2-ethiyigivcyl,
    B N-methyl-valyl, N-methyl-norvalyl, N-methyl-isoleucyl, N-methyl-2-tert-butylglycyl, N-methyl-2-ethylglycyl, or N-methyl-norleucyl, especially N-methyl-valyl, N-methyl-2-ethylglycyl, N-methyl-norleucyl, N-methyl-isoleucyl, or N-methyl-2-tert.butyl-glycyl;
    D prolyl, homoprolyl or thiazolidine-4-carbonyl, especially prolyl or thiazolidine-4-carbonyl;
    E prolyl, homoprolyl, thiazolidine-4-carbonyl, trans-4-fluoro-L-prolyl, cis-4-fluoro-L-prolyl, trans-4-chloro-L-prolyl or cis-4-chloro-L-prolyl, especially prolyl, trans-4-fluoro-prolyl, cis-4-fluoro-prolyl, trans-4-chloro-prolyl, or cis-4-chloro-prolyl;
    X ethyl, propyl, isopropyl, sec.butyl, tert.butyl or cyclo-propyl, especially ethyl, isopropyl, sec.butyl or tert.butyl;
    G L-2-tert.butylglycyl, D-2-Tert.butylglycyl, D-valyl, D-isoleucyl, D-leucyl or 2,2-dimethylglycyl residue;
    s 0 or 1.
    Preferred meanings for K are:
    —NH—C1-8-alkyl, —NH—C6-8-cycloalkyl, —NH—CH2-cyclohexyl, C1-4-alkyl-N—C1-6-alkyl, in which residues one CH2 group may be replaced by O, one H by phenyl or 1 or 2 H by F, except the N-methoxy-N-methylamino, N-benzylamino, or N-methyl-N-benzylamino residue, or K is






    More preferred K is
    —NHCH3, —NHCH2CH3, —NH(CH2)2CH3, —NH(CH2)3CH3, —NH(CH2)4—CH3, —NH(CH2)5CH3, —NH(CH2)6CH3, —NH(CH2)7CH3, —NHCH(CH3)2, —NHCH(CH3)CH2CH3, —NHCH(CH2CH3)2, —NHCH(CH2CH2CH3)2, —NHC(CH3)3, —NHCH(CH2CH3)CH2CH2CH3, —NHCH(CH3)CH(CH3)2, —NHCH(CH2CH3)CH(CH3)2, —NHCH(CH3)C(CH3)3, —NH-cyclohexyl, —NH-cycloheptyl, —NH-cyclooctyl, —N(CH3)OCH2CH3, —N(CH3)OCH2CH2CH3, —N(CH3)OCH(CH3)2, —N(OCH3)CH(CH3)2, —N(CH3)OCH2C6H5, —NH(CH2)2C6H5, —NH(CH2)3C6H5, —NHCH(CH3)C6H5, —NHC(CH3)2C6H5, —NHC(CH3)2CH2CH3, —NHC(CH3)(CH2CH3)2, —NHCH(CH3)CH(OH)C6H5, —NHCH2-cyclohexyl, —N(CH3)2, —N(CH2CH3)2, —N(CH2CH2CH3)2, —NHCH(CH2F)2, —NHC(CH3)CH═CH2, —NHC(CH3)2CN, —NHC(CH3)2C≡CH, —NHC(CH3)2CONH2, —NHCH[CH(CH3)2]2, —N(OCH3)CH2C6H5, —N(OCH3)CH2CH3, —N(OCH3)CH2CH2CH3, —N(OCH3)CH2CH2CH2CH3,






In one embodiment of the preferred compounds of formula I described above, is 0 and E is homoprolyl or hydroxyprolyl.
Especially preferred are compounds of the formula I where

    
    
        R1 and R2 are methyl,
        A is a valyl, isoleucyl, 2-tert.-butylglycyl residue
        B is a N-methylvalyl, N-methyl-isoleucyl, methyl-2tert.-butylglyeyl residue,
        D is a prolyl or thiazolidine-4-carbonyl residue
        E is a prolyl, cis-4-fluoro-L-prolyl, or cis-4-chloro-L-prolyl residue
        X is a isopropyl, sec.-butyl, or tert.-butyl residue,
        s is 0 and
        K is
    
    
    —NHCH(CH3)2, —NHCH(CH3)CH2CH3, —NHCH(CH2CH3)2, —NHCH(CH2CH2CH3)2, —NHC(CH3)3, —NHCH(CH2CH3)CH2CH2CH3, —NHCH(CH3)CH(CH3)2, —NHCH(CH2CH3)CH(CH3)2, —NHCH(CH3)C(CH3)3, —NH-cycloheptyl, —NH-cyclooctyl, —N(CH3)OCH2CH3, —N(CH3)OCH2CH2CH3, —N(CH3)OCH(CH3)2, —N(OCH3)CH(CH3)2, —N(CH3)OCH2C6H5, —NH(CH2)2C6H5, —NH(CH2)3C6H5, —NHCH(CH3)C6H5, —NHC(CH3)2C6H5, —NHC(CH3)2CH2CH3, NHC(CH3)(CH2CH3)2, —NHCH(CH3)CH(OH)C6H5, —NHCH(CH2F)2, —NHC(CH3)2CH2CH2OH, —NH(CH2CH2O)2CH7CH3, —NHC(CH3)2CH═CH2, —NHC(CH3)2CH(CH3)2, —N(OCH3)CH2CH3, —N(OCH3)CH2CH2CH3, —N(OCH3)CH2CH2CH2CH3, —NHC(CH3)2CN, —NHC(CH3)2C≡CH, —NHCH[CH(CH3)2]2, —NHC(CH3)2CONH2, —NHC(CH3)2CH2C6H5, —N(OCH3)C6H5, —N(OCH3)CH2C6H5,






This invention also provides methods for preparing the compounds of formula I, pharmaceutical compositions containing such compounds together with a pharmaceutically acceptable carrier and methods for using same for treating cancer in mammals.
The new compounds may be present as salts with physiologically tolerated acids such as: hydrochloric acid, citric acid, tartaric acid, lactic acid, phosphoric acid, methanesulfonic acid, acetic acid, formic acid, fumaric acid, malic acid, succinic acid, malonic acid, sulfuric acid, L-glutamic acid, L-aspartic acid, pyruvic acid, mucic acid, benzoic acid, glucuronic acid, oxalic acid, ascorbic acid and acetylglycine.
The novel compounds can be prepared by known methods of peptide chemistry. Thus, the peptides can be assembled sequentially from amino acids or by linking suitable small peptide fragments. In the sequential assemblage, starting at the C terminus the peptide chain is extended stepwise by one amino acid each time. In fragment coupling it is possible to link together fragments of different lengths, and the fragments in turn can be obtained by sequential assemblage from amino acids or themselves by fragment-coupling.
Both in the sequential assemblage and in the fragment coupling it is necessary to link the units by forming an amide linkage. Enzymatic and chemical methods are suitable for this.
Chemical methods for forming the amide linkage are described in detail by Mueller, Methoden der organischen Chemie Vol. XV/2, pp 1 to 264, Thieme Verlag, Stuttgart, 1974; Stewart, Young, Solid Phase Peptide Synthesis, pp 31 to 34, 71 to 82, Pierce Chemical Company, Rockford, 1984; Bodanszky, Klausner, Ondetti, Peptide Synthesis, pp 85 to 128, John Wiley & Sons, New York, 1976; The Practice of Peptide Synthesis, M. Bodanszky, A. Bodanszky, Springer-Verlag, 1994, and other standard works on peptide chemistry. Particular preference is given to the azide method, the symmetric and mixed anhydride method, in situ generated or performed active esters, the use of urethane protected N-carboxy anhydrides of amino acids and the formation of the amide linkage using coupling reagents, especially dicyclohexylcarbodiimide (DCC), diisopropylcarbodiimide (DIC), 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), pivaloylchloride, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI), n-propanephosphonic anhydride (PPA), N,N-bis(2-oxo-3-oxazolodinyl)-amidophosphoryl chloride (BOP-Cl), bromo-tris-pyrrolidino-phosphonium hexafluororophosphate (PyBrop), diphenylphosphoryl azide (DPPA), Castro's reagent (BOP, PyBop), O-benzotriazolyl-N,N,N′,N′-tetramethyluronium salts (HBTU), O-azabenzotriazolyl-N,N,N′,N′-tetramethyluronium salts (HATU), diethylphosphoryl cyanide (DEPCN), 2,5-diphenyl-2,3-dihydro-3-oxo-4-hydroxythiophene dioxide (Steglich's reagent; HOTDO) and 1,1′-carbonyldiimidazole (CDI). The coupling reagents can be employed alone or in combination with additives such as N,N-dimethyl-4-aminopyridine (DMAP), N-hydroxy-benzotriazole (HOBt, N-hydroxybenzotriazine (HOOBt), Azabenzotriazole, N-hydroxysuccinimide (HOSu) or 2-hydroxypyridine.
Whereas it is normally possible to dispense with protective groups in enzymatic peptide synthesis, reversible protection of reactive groups not involved in formation of the amide linkage is necessary for both reactants in chemical synthesis. Three conventional protective group techniques are preferred for the chemical peptide synthesis: the benzyloxycarbonyl (Z), the t-butoxycarbonyl (Boc) and the 9-fluorenylmethoxycarbonyl (Fmoc) techniques.
Identified in each case is the protective group on the alpha-amino group of the chain-extending unit. A detailed review of amino-acid Protective groups is given by Mueller, Methoden der organischem Chemie vol. XV/1, pp 20 to 906, Thieme Verlag, Stuttgart, 1974. The units employed for assembling the peptide chain can be reacted in solution, in suspension or by a method similar to that described by Merrifield in J. Amer. Chem. Soc. 85 (1963) 2149.
Suitable for peptide synthesis in solution are all solvents which are inert under the reaction conditions, especially water, N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), acetonitrile, dichloromethane (DCM), ethyl acetate, 1,4-dioxane, tetrahydrofuran (THF), N-methyl-2-pyrrolidone (NMP) and mixtures of the said solvents.
Peptide synthesis on the polymeric support can be carried out in all inert organic solvents in which the amino-acid derivatives used are soluble. However, preferred solvents additionally have resin-swelling properties, such as DMF, DCM, NMP, acetonitrile and DMSO, and immixtures of these solvents. After synthesis is complete, the peptide is cleaved off the polymeric support. The conditions under which cleavage off the various resin types is possible are disclosed in the literature. The cleavage reactions most commonly used are acid- and palladium-catalyzed, especially cleavage in liquid anhydrous hydrogen fluoride, in anhydrous trifluoromethanesulfonic acid, in dilute or concentrated trifluoroacetic acid, palladium-catalyzed cleavage in THF or THF-DCM mixturers in the presence of a weak base such as morpholine or cleavage in acetic acid/dichloromethane/trifluoroethanol mixtures. Depending on the chosen protective groups, these may be retained or likewise cleaved off under the cleavage conditions.
Partial deprotection of the peptide may also be worthwhile when certain derivatization reactions are to be carried out.
Peptides dialkylated at the N-terminus can be prepared either by coupling on the appropriate N,N-di-alkylamino acids in solution or on the polymeric support, by reductive alkylation of the resin-bound peptide in DMF/1% acetic acid with NaCNBH3 and the appropriate aldehydes, by hydrogenation of the peptide in solution in the presence of aldehyde or ketone and Pd/C.
The various non-naturally occurring amino acids as well as the various non-amino acid moieties disclosed herein may be obtained from commercial sources or synthesized from commercially available materials using methods known in the art. For example, amino acids building blocks with R1 and R2 moieties can be prepared according to E. Wuensch, Houben Weyl, Meth. d. Org. Chemie, Bd. XV, 1, p. 306 following, Thieme Verlag Stuttgart 1974 and Literature cited therein.
The compounds of this invention may be used to inhibit or otherwise treat solid tumors (e.g. tumors of the lung, breast, colon, prostate, bladder, rectum, or endometrial tumors) or hematological malignancies (e.g. leukemias, lymphomas) by administration of the compound to the mammal.
It is a special advantage of the new compounds that they are very resistant to enzymatic degradation and can also be administered orally.
Administration may be by any of the means which are conventional for pharmaceutical, preferably oncological, agents, including oral and parenteral means such as subcutaneously, intravenously, intramuscularly and intraperitoneally.
The compounds may be administered alone or in the form of pharmaceutical compositions containing a compound of formula I together with a pharmaceutically accepted carrier appropriate for the desired route of administration. Such pharmaceutical compositions may be combination products, i.e., may also contain other therapeutically active ingredients.
The dosage to be administered to the mammal will contain an effective tumor-inhibiting amount of active ingredient which will depend upon conventional factors including the biological activity of the particular compound employed; the means of administration; the age, health and body weight of the recipient; the nature and extent of the symptoms; the frequency of treatment; the administration of other therapies; and the effect desired. A typical daily dose will be about 0.05 to 50 milligrams per kilogram of body weight on oral administration and about 0.01 to 20 milligrams per kilogram of body weight on parenteral administration.
The novel compounds can be administered in conventional solid or liquid pharmaceutical administration forms, e.g. uncoated or (film-)coated tablets, capsules, powders, granules, suppositories or solutions. These are produced in a conventional manner. The active substances can for this purpose be processed with conventional pharmaceutical aids such as tablet binders, fillers preservatives, tablet disintegrants, flow regulators, plasticizers, wetting agents, dispersants, emulsifiers, solvents, sustained release compositions, antioxidants and/or propellant gases (cf. H. Sucker et al.: Pharmazeutische Technologic, Thieme-Verlag, Stuttgart, 1978). The administration forms obtained in this way normally contain 1-90% by weight of the active substance. The following examples are intended to illustrate the invention. The proteinogenous amino acids are abbreviated in the examples using the known three-letter code. Other abbreviations used: Me2Val=N,N-dimethylvaline, MeVal=N-methylvaline.
EXAMPLES
A. General Procedures
I. The Peptides of the Present Invention are either Synthesized by Classical Solution Synthesis Using Standard Z- and Boc-Methodology as Described above or by Standard Methods of Solid-Phase Synthesis Using Boc and Fmoc Protective Group Techniques.
In the case of solid phase synthesis, the N,N-dialkylpenta- or hexapeptide acids are liberated from the solid support and further coupled with the corresponding C-terminal amines in solution. BOP-Cl and PyBrop were used as reagents for coupling of the amino acid following the N-methylamino acids. The reaction times were correspondingly increased. For reductive alkylation of the N-terminus, the peptide-resin was deprotected at the N terminus and then reacted with a 3-fold molar excess of aldehyde or ketone in DMF/1% acetic acid with addition of 3 equivalents of NaCNBH3. After the reaction was complete (negative Kaisertest) the resin was washed several times with water, isopropanol, DMF and dichloromethane.
In solution synthesis, the use of either Boc-protected amino acid NCAs (N-tert.-butyloxycarbonyl-amino acid-N-carboxy-anhydrides), Z-protected amino acid NCAs (N-benzyloxycarbonyl-amino acid-N-carboxy-anhydrides), or the use of pivaloylchloride as condensing agent respectively is most advantageous for coupling of the amino acid following the N-methylamino acids. Reductive alkylation of the N terminus can e.g. be achieved by reaction of the N-terminally deprotected peptides or amino acids with the corresponding aldehydes or ketones using NaCNBH3 or hydrogen, Pd/C.
II. Purification and Characterization of the Peptides
Purification was carried out by gel chromatography (SEPHADEX G-10, G-15/10% HOAc, SEPHADEX LH20/MeOH), medium pressure chromatography (stationary phase: HD-SIL C-18, 20-45 mikron, 100 Angstrom; mobile phase: gradient with A=0.1% TFA/MeOH, B=0.1% TFA/water), or preparative HPLC (stationary phase: Waters Delta-Pak C-18, 15 mikron, 100 Angstrom; mobile phase: gradient with A=0.1% TFA/MeOH, 3=0.1% TFA/water).
The purity of the resulting products was determined by analytical HPLC (stationary phase: 100 2.1 mm VYDAC C-18, 5 1, 300 A; mobile phase: acetonitrile-water gradient, buffered with 0.1% TFA, 40.degree. C.).
Characterization was by amino-acid analysis and fast atom bombardment mass spectroscopy.
B. Specific Procedures









Example 1



(SEQ ID NO: 1)



Me.2Val-Val-MeVal-Pro-Pro-NHCH(CH3)2



 



a) Z-MeVal-Pro-OME






66.25 g (250 mmol) Z-MeVal-OH were dissolved in 250 ml dry dichloromethane. After addition of 36.41 ml (262.5 mmol) triethylamine, the reaction mixture was cooled to −25° C. and 32.27 ml (262.5 mmol) pivaloyl chloride were added. After stirring for 2.5 h, 41.89 g (250 mmol) H-Pro-OMe×Ch1 in 250 ml dichloromethane, neutralized with 36.41 ml (262.5 mmol) triethylamine at 0.degree. C., were added to the reaction mixture. Stirring continued for 2 h at −25.degree. C. and overnight at room temperature. The reaction mixture was diluted with dichloromethane and thoroughly washed with saturated aqueous NaHCO3 solution (3×.), water (1×), 5% citric acid (3×) and saturated NaCl solution. The organic phase was dried over sodium sulfate and evaporated to dryness. The residue (91.24 g) was stirred with petroleum ether overnight and filtered. 62.3 g of product were obtained.









b) H-MeVal-Pro-OMe






48.9 g (130 mmol) Z-MeVal-Pro-OMe were dissolved in 490 ml methanol. After addition of 10.9 ml (130 mmol) concentrated hydrochloric acid and 2.32 g 10% Palladium/charcoal, the reaction mixture was hydrogenated. Filtration and evaporation to dryness yielded 36.32 g of the product.









c) Z-Val-MeVal-Pro-OMe






18.1 g (65 mmol) H-MeVal-Pro-OMe, 21.6 g (78 mmol) Z-Val-N-carboxyanhydride and 22.8 ml (130 mmol) diisopropylethylamine were stirred in 110 ml DMF at 40° C. for 2 d. After evaporation of DMF, dichloromethane was added and the organic phase washed with saturated aqueous NaHCO3 solution (3×), water (1×), 4% citric acid (3×) and saturated NaCl solution. The organic phase was dried over sodium sulfate and evaporated to dryness. The product (29.3 g) was obtained as a viscous oil.









d) H-Val-MeVal-Pro-OMe






29.3 g (61.6 mmol) of Z-Val-MeVal-Pro-OMe were dissolved in 230 ml methanol. After addition of 1.15 g 10% Palladium/charcoal, the reaction mixture was hydrogenated. Filtration and evaporation to dryness yielded 21.96 g of the product.










e) Z-Val-Val-MeVal-Pro-Ome
(SEQ ID NO: 2)






15.29 g (61 mmol) Z-Val-OH and 21.96 g (61 mmol) H-Val-MeVal-Pro-OMe were dissolved in 610 ml dichloromethane and cooled to 0.degree. C. After addition of 8.16 ml (73.2 mmol) N-Methylmorpholine, 2.77 g (20.3 mmol) HOBt and 11.73 g (61 mmol) EDCI, the reaction mixture was stirred overnight at room temperature, diluted with dichloromethane and thoroughly washed with saturated aqueous NaHCO3 solution (3×), water (1×), 5% citric acid (3×) and saturated NaCl solution. The organic phase was dried over sodium sulfate and evaporated to dryness to yield 31.96 g of the product.










f) Z-Val-Val-MeVal-Pro-OH
(SEQ ID NO: 2)






31.96 g (57 mmol) Z-Val-Val-MeVal-Pro-OMe (SEQ ID NO: 2) were dissolved in 250 ml methanol. 102.6 ml of a 1 N LiOH solution was added and the mixture stirred overnight at room temperature. After addition of 500 ml water, the aqueous phase was washed three times with ethyl acetate, adjusted to pH 2 at 0° C. and extracted three times with ethyl acetate. The organic phase was dried over sodium sulfate and evaporated to dryness yielding 30.62 g of the desired product as a white solid.









(SEQ ID NO: 1)










g)
Z-Val-Val-MeVal-Pro-Pro-NHCH(CH3)2






2 g (3.35 mmol) Z-Val-Val-MeVal-Pro-OH (SEQ ID NO: 2) and 0.664 g (3.35 mmol) H-Pro-NHCH(CH3)2 were dissolved in 34 ml of dry dichloromethane. After cooling to 0° C., 1.35 ml (12.1 mmol) N-methylmorpholine, 0.114 g (0.84 mmol) HOBt and 0.645 g (3.35 mmol) EDCI were added and the reaction mixture stirred overnight at room temperature. 80 ml dichloromethane were added and the organic phase thoroughly washed with saturated aqueous NaHCO3 solution (3×), water (1×), 5% citric acid (3×) and saturated NaCl solution (1×). The organic phase was dried over sodium sulfate and evaporated to dryness to yield 1.96 g of the product which was used in the next reaction without further purification.









(SEQ ID NO: 1)










h)
Me2 Val-Val-MeVal-Pro-Pro-NHCH(CH3)2






1.96 g Z-Val-Val-MeVal-Pro-Pro-NHCH(CH3)2 (SEQ ID NO: 2) were dissolved in 11 ml methanol. 0.054 g 10% Pd/C were added under nitrogen atmosphere and the reaction mixture hydrogenated at room temperature for 4 h. After addition of 0.86 ml (11.24 mmol) of a 37% aqueous formaldehyde solution and 0.281 g 10% Pd/C, hydrogenation was continued for 5 h. Filtration and evaporation of the solvent gave rise to 2.77 g of crude product. Further purification was achieved by dissolving the peptide in water, adjusting the pH to 2 and extracting the aqueous phase three times with ethyl acetate. The aqueous phase was then adjusted to pH 8-9 and extracted four times with dichloromethane. The organic phase was dried over sodium sulfate to yield 1.37 g of purified product as a white foam. The compound was further purified using medium pressure liquid chromatography (10-50% A in 10 min.; 50-90% A in 320 min.). Fractions containing the product were combined, lyophilized, redissolved in water and the pH adjusted to 9 with 1 N LiOH. After extraction with dichloromethane, the organic phase was dried over sodium sulfate and evaporated to dryness. Lyophilization led to 500 mg of pure product, which was characterized by fast atom bombardment mass spectrometry ([M+H]+=593).









Example 2



(SEQ ID NO: 1)



Me2 Val-Val-MeVal-Pro-Pro-NHC(CH3)3



 



(SEQ ID NO: 1)



i) Z-Val-Val-MeVal-Pro-Pro-NHC(CH3)3






2 g (3.35 mmol) Z-Val-Val-MeVal-Pro-OH (SEQ ID NO: 2) and 0.692 g (3.35 mmol) H-Pro-NHC(CH3)3 were dissolved in 34 ml of dry dichloromethane. After cooling to 0° C., 1.35 ml (12.1 mmol) N-methylmorpholine, 0.114 g (0.84 mmol) HOBt and 0.645 g (3.35 mmol) EDCI were added and the reaction mixture stirred overnight at room temperature. 80 ml dichloromethane were added and the organic phase thoroughly washed with saturated aqueous NaHCO3 solution (3×), water (1×), 5% citric acid (3×) and saturated NaCl solution (1×). The organic phase was dried over sodium sulfate and evaporated to dryness to yield 1.8 g of the product which was used in the next reaction without further purification.









(SEQ ID NO: 1)



k) Me2 Val-Val-MeVal-Pro-Pro-NHC(CH3)3






1.8 g Z-Val-Val-MeVal-Pro-Pro-NHC(CH3)3 (SEQ ID NO: 1) were dissolved in 10 ml methanol. 0.049 g 10% Pd/C were added under nitrogen atmosphere and the reaction mixture hydrogenated at room temperature for 4 h. After addition of 0.86 ml (11.24 mmol) of a 37% aqueous formaldehyde solution and 0.252 g 10% Pd/C, hydrogenation was continued for 5 h. Filtration and evaporation of the solvent gave rise to 1.82 g of crude product. The compound was further purified using medium pressure liquid chromatography 10-50% A in 10 min.; 50-90% A in 320 min.). Fractions containing the product were combined, lyophilized, redissolved in water and the pH adjusted to 9 with 1 N LiOH. After extraction with dichloromethane, the organic phase was dried over sodium sulfate and evaporated to dryness. Lyophilization led to 547 mg of pure product, which was characterized by fast atom bombardment mass spectrometry ([M+H]+=607).
The following compounds were prepared or can be prepared according to examples 1 and 2:


















3.
Xaa
Val
Xab
Pro
Xac



4.
Xaa
Val
Xab
Pro
Xad


5.
Xaa
Val
Xab
Pro
Xae


6.
Xaa
Val
Xab
Pro
Xaf


7.
Xaa
Val
Xab
Pro
Xag


8.
Xaa
Val
Xab
Pro
Xah


9.
Xaa
Val
Xab
Pro
Xai


10.
Xaa
Val
Xab
Pro
Xak


11.
Xaa
Val
Xab
Pro
Xal


12.
Xaa
Val
Xab
Pro
Xam


13.
Xaa
Val
Xab
Pro
Xan


14.
Xaa
Val
Xab
Pro
Xao


15.
Xaa
Val
Xab
Pro
Xap


16.
Xaa
Val
Xab
Pro
Xaq


17.
Xaa
Val
Xab
Pro
Xar


18.
Xaa
Val
Xab
Pro
Xas


19.
Xaa
Val
Xab
Pro
Xat


20.
Xaa
Val
Xab
Pro
Xau


21.
Xaa
Val
Xab
Pro
Xav


22.
Xaa
Val
Xab
Pro
Xaw


23.
Xaa
Val
Xab
Pro
Xax


24.
Xdd
Val
Xab
Pro
Xay


25.
Xaa
Val
Xab
Pro
Xaz


26.
Xaa
Val
Xab
Pro
Xba


27.
Xaa
Val
Xab
Pro
Xbb


28.
Xaa
Val
Xab
Pro
Xay


29.
Xaa
Val
Xab
Pro
Xbd


30.
Xaa
Val
Xab
Pro
Xbe


31.
Xaa
Val
Xab
Pro
Xbf


32.
Xaa
Val
Xab
Pro
Xbg


33.
Xaa
Val
Xab
Pro
Xbh


34.
Xaa
Val
Xab
Pro
Xbi


35.
Xaa
Val
Xab
Pro
Xbk


36.
Xaa
Val
Xab
Pro
Xbl


37.
Xaa
Val
Xab
Pro
Xbm


38.
Xaa
Val
Xab
Pro
Xbn


39.
Xaa
Val
Xab
Pro
Xb0


40.
Xaa
Val
Xab
Pro
Xbp


41.
Xaa
Val
Xab
Pro
Xbq


42.
Xaa
Val
Xab
Pro
Xbr


43.
Xaa
Val
Xab
Pro
Xbx


44.
Xaa
Val
Xab
Pro
Xbt


45.
Xaa
Val
Xab
Pro
Xbu


46.
Xaa
Val
Xab
Pro
Xbv


47.
Xaa
Val
Xab
Pro
Xbw


48.
Xaa
Val
Xab
Pro
Xbx


49.
Xaa
Val
Xab
Pro
Xby


50.
Xaa
Val
Xab
Pro
Xbz


51.
Xaa
Val
Xab
Pro
Xca


52.
Xaa
Val
Xab
Pro
Xcb


53.
Xaa
Val
Xab
Pro
Xcc


54.
Xaa
Val
Xab
Pro
Xcd


55.
Xaa
Val
Xab
Pro
Xce


56.
Xaa
Val
Xab
Pro
Xcf


57.
Xaa
Xdf
Xab
Pro
Xay


58.
Xaa
Val
Xab
Pro
Xch


59.
Xaa
Val
Xab
Pro
Xci


60.
Xaa
Val
Xab
Pro
Xck


61.
Xaa
Val
Xab
Pro
Xcl


62.
Xaa
Val
Xab
Pro
Xcm


63.
Xaa
Val
Xab
Pro
Xcn


64.
Xaa
Val
Xab
Pro
Xco


65.
Xaa
Val
Xab
Pro
Xcp


66.
Xaa
Val
Xab
Pro
Xcq


67.
Xaa
Val
Xab
Pro
Xcr


68.
Xaa
Val
Xab
Pro
Xcs


69.
Xaa
Val
Xab
Pro
Xct


70.
Xaa
Val
Xab
Pro
Xcu


71.
Xcx
Val
Xab
Pro
Xcv


72.
Xcx
Val
Xab
Pro
Xcv


73.
Xaa
Val
Xab
Pro
Pro
Xcy


74.
Xaa
Val
Xab
Pro
Pro
Xcz


75.
Xaa
Val
Xda
Pro
Xcv


76.
Xaa
Xdb
Xab
Pro
Xcv


77.
Xdc
Val
Xab
Pro
Xcv


78.
Xaa
Ile
Xab
Pro
Xcv


79.
Xdd
Val
Xab
Pro
Xcv


80.
Xde
Val
Xab
Pro
Xcv


81.
Xaa
Xdf
Xab
Pro
Xcv


82.
Xaa
Val
Xab
Pro
Xcg


83.
Xaa
Val
Xab
Pro
Pro
Xdg


84.
Xaa
Val
Xab
Pro
Pro
Xdh


85.
Xaa
Val
Xab
Pro
Pro
Xdi


86.
Xaa
Val
Xab
Pro
Pro
Xdk


87.
Xaa
Val
Xdl
Pro
Xcv


88.
Xde
Val
Xab
Pro
Xay


89.
Xaa
Val
Xdl
Pro
Xay


90.
Xaa
Val
Xab
Pro
Xdm


91.
Xaa
Val
Xab
Pro
Xdn


92.
Xaa
Val
Xab
Pro
Xdo


93.
Xaa
Val
Xab
Pro
Xdp


94.
Xaa
Val
Xab
Pro
Xdq


95.
Xaa
Val
Xab
Pro
Pro
Xdr


96.
Xaa
Val
Xab
Pro
Xds


97.
Xaa
Val
Xbc
Pro
Xcv


98.
Xaa
Ile
Xab
Pro
Xay


99.
Xcw
Val
Xab
Pro
Xay


100.
Xaa
Val
Xbc
Pro
Xal


101.
Xaa
Val
Xdl
Pro
Xal


102.
Xaa
Xdf
Xab
Pro
Xal


103.
Xaa
Ile
Xab
Pro
Xal


104.
Xdd
Val
Xab
Pro
Xal


105.
Xde
Val
Xab
Pro
Xal


106.
XcX
Val
Xab
Pro
Xcy


107.
Xcw
Val
Xab
Pro
Xal


108.
Xcx
Val
Xab
Pro
Xal


109.
Xcw
Val
Xab
Pro
Xav


110.
Xcx
Val
Xab
Pro
Xav


111.
Xcw
Val
Xab
Pro
Xaw


112.
Xcx
Val
Xab
Pro
Xaw


113.
Xab
Val
Xab
Pro
Xay


114.
Xab
Val
Xab
Pro
Xcv


115.
Xab
Val
Xab
Pro
Xal


116.
Xab
Val
Kab
Pro
Xam


117.
Xab
Val
Xab
Pro
Xam


118.
Xab
Val
Xab
Pro
Xao


119.
Xab
Val
Xab
Pro
Xay


120.
Xab
Val
Xab
Pro
Xaw


121.
Xab
Val
Xab
Pro
Xau


122.
Xab
Val
Xab
Pro
Xau


123.
Xab
Val
Xab
Pro
Xbf


124.
Xab
Val
Xab
Pro
Xbm


125.
Xab
Val
Xab
Pro
Xbm


126.
Xab
Val
Xab
Pro
Xbo


127.
Xab
Val
Xab
Pro
Xch


128.
Xaa
Val
Xab
Pro
Xdt


129.
Xaa
Val
Xab
Pro
Xdu


130.
Xaa
Val
Xab
Pro
Xdv


131.
Xaa
Val
Xab
Pro
Xdw


132.
Xaa
Val
Xab
Pro
Xdx


133.
Xaa
Val
Xab
Pro
Xdy


134.
Xaa
Val
Xab
Pro
Xdz


135.
Xaa
Val
Xab
Pro
Xea


136.
Xaa
Val
Xab
Pro
Xeb


137.
Xaa
Val
Xab
Pro
Xec


138.
Xaa
Val
Xab
Pro
Xed


139.
Xaa
Val
Xab
Pro
Xef


140.
Xaa
Val
Xab
Pro
Xeg


141.
Xaa
Val
Xab
Pro
Xeh


142.
Xaa
Val
Xab
Pro
Xei


143.
Xaa
Val
Xab
Pro
Xek


144.
Xaa
Val
Xab
Pro
Xel


145.
Xaa
Val
Xab
Pro
Xem


146.
Xaa
Val
Xab
Pro
Xen


147.
Xaa
Val
Xab
Pro
Xeo


148.
Xaa
Val
Xab
Pro
Xep


149.
Xaa
Val
Xab
Pro
Xeq


150.
Xaa
Val
Xab
Pro
Xer


151.
Xaa
Val
Xab
Pro
Xcg









Examples for the MS-characterization of the synthesized novel compounds are given in the following table.








TABLE I







Sequence Identification of Compounds Prepared


According to Examples 1 and 2










EXAMPLE
Fast atom bombardment MS analysis.



[No.]
[Mol.-Weight (measured)]














3.
565



4.
579



5.
593



6.
607



7.
621



8.
635



11.
607



12.
607



13.
621



14.
649



15.
635



16.
635



17.
635



18.
635



19.
621



20.
621



21.
635



22.
635



25.
633



26.
647



27.
661



31.
623



32.
671



33.
667



34.
631



35.
655



36.
655



37.
669



38.
621



39.
635



41.
649



42.
621



43.
633



44.
667



45.
607



46.
647



47.
668



48.
655



49.
669



50.
685



51.
629



52.
625



53.
721



55.
579



58.
623



61.
597



62.
621



63.
609



64.
625



65.
635



66.
591



67.
715



68.
685



69.
685



70.
591



71.
607



72.
621



74.
706



75.
579



76.
579



77.
579



78.
607



79.
607



80.
607



81.
607



82.
637



83.
692



84.
706



85.
706



86.
706



87.
607



90.
635



92.
659



93.
617



94.
636



95.
678



128.
671



131.
625



139.
625



151.
637










Compound Number(s)

    1-56, 58-72, 75, 77, 79, 80, 82,
    87-94, 96, 97, 99-101, 104-151
    73, 74, 83-86, 95,
    57, 76, 81, 102
    78, 98, 103

The symbols Xaa in the summary have the following meanings:

















































Compounds of this invention may be assayed for anti-cancer activity by conventional methods, including for example, the methods described below.
A. In Vitro Methodology
Cytotoxicity was measured using a standard methodology for adherent cell lines such as the microculture tetrazolium assay (MTT). Details of this assay have been published (Alley, M C et al, Cancer Research 48:589-601, 1988). Exponentially growing cultures of tumor cells such as the HT-29 colon carcinoma or LX-1 lung tumor are used to make microtiter plate cultures. Cells are seeded at 3000 cells per well in 96-well plates (in 150.mu.l or media), and grown overnight at 37° C. Test compounds are added, in 10-fold dilutions [varying from 100.4 M to 100.10 M. Cells are then incubated for 72 hours. To determine the number of viable cells in each well, the MTT dye is added (50 μl or 3 mg/ml solution of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide in saline). This mixture is incubated at 37° C. for 5 hours, and then 50 μl of 25% SDS, pH2 is added to each well. After an overnight incubation, the absorbance of each well at 550 nm is read using an ELISA reader. The values for the mean+/−SD of data from replicated wells are calculated, using the formula % T/C (% viable cells treated/control).




  
    
      
        
          
            
              O
              ⁢
              
                
              
              ⁢
              D
              ⁢
              
                
              
              ⁢
              of
              ⁢
              
                
              
              ⁢
              treated
              ⁢
              
                
              
              ⁢
              cells
            
            
              O
              ⁢
              
                
              
              ⁢
              D
              ⁢
              
                
              
              ⁢
              of
              ⁢
              
                
              
              ⁢
              control
              ⁢
              
                
              
              ⁢
              cells
            
          
          ×
          100
        
        +
        
          %
          ⁢
          
            
          
          ⁢
          T
          ⁢
          
            /
          
          ⁢
          C
        
      
    
    
      
        
      
    
  




The concentration of test compound which gives a T/C of 50% growth inhibition was designated as the IC50 value.
B. In Vivo Methodology
Compounds of this invention were further tested in pre-clinical assay for in vivo activity which is indicative of clinical utility. Such assays were conducted with nude mice into which tumor tissue, preferably of human origin, had been transplanted (xenografted), as is well known in this field. Test compounds were evaluated for their anti-tumor efficacy following administration to the xenograft-bearing mice.
More specifically, human breast tumors (MX-1) which had been grown in athymic nude mice were transplanted into new recipient mice, using tumor fragments which were about 50 mg in size. The day of transplantation was designated as day 0. Six to ten days later, mice were treated with the test compounds given as an intravenous injection or orally, in groups of 5-10 mice at each dose. Compounds were given every other day, for 3 weeks, at doses from 1-200 mg/kg body weight.
Tumor diameters and body weights were measured twice weekly. Tumor volumes were calculated using the diameters measured with Vernier calipers, and the formula

(Length×width2)/2=mm3 of tumor volume

Mean tumor volumes are calculated for each treatment group, and T/C values determined for each group relative to the untreated control tumors.
The new compounds possess good tumor inhibiting properties.

## Claims

1. A method of treating a solid tumor in a mammal, comprising administering to the mammal an effective amount of a peptide, wherein the peptide is of the formula I:









(SEQ ID NO: 1)



(I)



Me2Val-Val-MeVal-Pro-Pto-NHC(CH3)3






or a pharmaceutically acceptable salt thereof.

2. The method of claim 1 wherein the pharmaceutically acceptable salt is a hydrochloride salt.

3. The method of claim 1, wherein the solid tumor is a tumor of the lung, breast, colon, prostate, bladder, rectum, or an endometrial tumor.

4. The method of claim 1, wherein the peptide is of formula I is orally or parenterally administered to the mammal.

5. The method of claim 1, wherein the peptide is of formula I is subcutaneously, intravenously, intramuscularly or intraperitoneally administered to the mammal.

6. The method of claim 4, wherein the peptide is of formula I is orally administered at a dose of about 0.05 to 50 milligrams per kilogram of body weight.

7. The method of claim 4, wherein the peptide of formula I is parenterally administered at a dose of about 0.01 to 20 milligrams per kilogram of body weight.

8. The method of claim 1, wherein the peptide of formula I is in the in the form of a pharmaceutical composition.

9. The method of claim 1, wherein the mammal is human.

10. A method of treating a hematological malignancy in a mammal, comprising administering to the mammal an effective amount of a peptide, wherein the peptide is of the formula I:









(SEQ ID NO: 1)



(I)



Me2Val-Val-MeVal-Pro-Pro-NHC(CH3)3






or a pharmaceutically acceptable salt thereof.

11. The method of claim 10 wherein the pharmaceutically acceptable salt is a hydrochloride salt.

12. The method of claim 10, wherein the hematological malignancy is a leukemia or a lymphoma.

13. The method of claim 10, wherein the peptide of formula I is orally or parenterally administered to the mammal.

14. The method of claim 10, wherein the peptide of formula I is subcutaneously, intravenously, intramusculary or intraperitoneally administered to the mammal.

15. The method of claim 13, wherein the peptide of formula I is orally administered at a dose of about 0.05 to 50 milligrams per kilogram of body weight.

16. The method of claim 13, wherein the peptide of formula I is parenterally administered at a dose of about 0.01 to 20 milligrams per kilogram of body weight.

17. The method of claim 10 wherein the peptide of formula I is in the in the form of a pharmaceutical composition.

18. The method of claim 10, wherein the mammal is human.